Earthquake resistant system

ABSTRACT

An earthquake resistant column or post connection to a footing or foundation comprises: A. A TURNTABLE AND A BASE SUPPORTING THE TURNTABLE FOR ROTATION ABOUT A GENERALLY UPRIGHT AXIS, B. AN ELONGATED TRACK ON AND EXTENDING TRANSVERSELY OF THE TURNTABLE, AND C. COLUMN SUPPORT MEANS INCLUDING A BEARING SYSTEM CARRIED BY THE TRACK FOR MOVEMENT RELATIVELY ALONG THE TRACK IN OFF-CENTER RELATION TO SAID AXIS ACCOMPANIED BY TURNTABLE ROTATION ABOUT SAID AXIS IN RESPONSE TO EARTHQUAKE INDUCED MOVEMENT OF SAID BASE.

United States Patent [1 1 Eskijian 1 Oct. 2, 1973 I EARTHQUAKE RESISTANT SYSTEM [76] Inventor: Luther Eskijian, 2223 Midlothian Dr., Altadena, Calif. 9I001 [22] Filed: July 19, 1972 [21] Appl. No.: 273,103

[51] Int. Cl E04h 9/02 [58] Field of Search 52/65, I67, 573; 248/20 [56] References Cited UNITED STATES PATENTS 2,055,000 9/I936 Bacigalupo 52/l67 2,208,872 7/1940 Ropp 52/167 2,705,928 4/1955 .Pont....- 52/167 X 3,110,464 1I/l963 Baratoff et al 248/20 FOREIGN PATENTS OR APPLICATIONS 1,274,932 9/1961 France .t 52/167 Primary ExaminerAlfred C. Perham Att0rneyWilliam W. Haefliger et al.

[57] ABSTRACT An earthquake resistant column or post connection to a footing or foundation comprises:

a. a turntable and a base supporting the turntable for rotation about a generally upright axis,

)2. an elongated track on and extending transversely of the turntable, and

c. column support means including a bearing system carried by the track for movement relatively along the track in off-center relation to said axis accompanied by turntable rotation about said axis in response to earthquake induced movement of said base.

10 Claims, 7 Drawing Figures Patented Oct. 2, 1973 3,762,114

3 Sheets-Sheet 1 Patented Oct. 2, 1973 3 Sheets-Sheet 2 EA RTHQUAKE RESISTANT SYSTEM BACKGROUND OF THE INVENTION This invention relates generally to the construction of load bearing structures to resist destruction during earthquakes; more particularly, it concerns an earthquake resistant connection between a load imposing column or post and a footing or foundation.

When extreme earthquake forces and earth displacements are transmitted to columns or posts via footings, structural failures commonly occur. One reason for such failure lies in the inability of connections between columns and footings to sufficiently accommodate lateral movement, i.e. movement generally transverse to the column height direction. There are no present established means to obtain the results afforded by this invention, to my knowledge.

SUMMARY OF THE INVENTION It is a major object of the invention to provide an earthquake resistant column or post connection to a footing or foundation. Basically, the invention is embodied in the combination that comprises:

a. a turntable and a base supporting the turntable for rotation about a generally upright axis,

b. an elongated track on and extending transversely of the turntable, and

0. column support means including a bearing system carried by the track for movement relatively along the track in off-center relation to said axis accompanied by turntable rotation about said axis in response to earthquake induced movement of said base.

As will be seen, the bearing may typically comprise rollers engaging the track and the support means may include a universal joint of special design carried by the rollers, the joint and rollers located to successively transmit column imposed loading to the track while accommodating soil rotation or movement relative to the track and column. Further, a carriage connected between the universal joint and roller bearing may be confined by the track in the form ofa channel member.

Additional objects include the provision of roller.

bearing means interposed between the turntable and base to maintain the turntable centered with respect to the upright axis while transmitting column imposed loading to the base during table rotation; and the location of such roller bearing means generally beneath the track and also peripherally of the turntable, as will be seen.

Additional advantages of the earthquake resistant structure include adaptation of concealment with retention of structural integrity; capacity to withstand earthquake induced displacement in any lateral direction; adaptation to design meeting standard building practices for columns to footings and/or ground level beams, and to withstand any loads; use in existing buildings having column designs; conformance to stable equilibrium positioning or to neutral equilibrium positioning; compatibility with vertical column displacements; and use for dynamic response of any structural system such as for bridges, vessels, equipment loads, etc.

These and other object and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings, in which:

DRAWING DESCRIPTION FIG. 1 is a plan view of one form of apparatus incorporating the invention;

FIG. 2 is an enlarged elevation taken in section on lines 2-2 of FIG. 1;

FIG. 3 is an enlarged elevation taken in section on lines 3-3 of FIG. 1;

FIG. 4 is a fragmentary bottom plan view taken on lines 44 of FIG. 3;

FIG. 5 is an enlarged section taken in elevation on lines 55 of FIG. 1;

FIG. 6 is a section taken in elevation on lines 66 of FIG. 5; and

FIG. 7 is an elevation showing a structure supported by multiple means incorporating the invention.

DETAILED DESCRIPTION In the drawings, a base, generally indicated at 10, supports a turntable 11 for rotation about a generally upright axis 12. The base may include a bottom metal plate 13 seated on a footing such as concrete slab or layer 14, and fasteners such as bolts 15 and nuts 16 may be employed to anchor an outer portion 17 of plate to the slab, as shown. The concrete footing may be poured so as to extend over plate outer annular portion 17 and against the outer side of upright annular wall 18 of the base, for securely anchoring the base to the footing. Circularly spaced gusset plates 19 interconnect the metallic wall 18 with the bottom plate outer extension 17.

While the turntable 11 may have various forms, it may advantageously include a disc shaped metal plate 20 the outer periphery 20a of which extends proximate the inner periphery 18a of the wall. The support of the turntable for rotation about axis 12 may be provided by certain roller bearing means interposed between the turntable and the base to maintain the turntable centered with respect to axis 12. Such roller bearing means may advantageously include first rollers 22 suitably pivotally carried at 23 by the turntable proximate its periphery 20a to engage the inner side 18a of base wall 18; second rollers 24 located beneath the turntable and carried for rotation about axes 25 extending generally radially relative to upright axis 12; and third rollers 26 located beneath the turntable and carried for rotation about axes 27 extending generally radially outwardly as well as upwardly relative to axis 12. Like rollers 24 are advantageously symmetrically located at opposite sides of axis 12, carriages 28 supporting them as via suitable pivots 29 to seat on bottom plate 13; similarly, like tandem pairs of rollers 26 are advantageously symmetrically located at opposite sides of axis 12, carriages 30 supporting them as via suitable pivots 31 to seat and roll on annular and frusto-conical guideway 32. The latter is carried by and affixed to the base, as shown, so that it may be considered as part of the base. An annu lar cover ring 33 is releasably attached tothe ring 18 to closely overlap the periphery of turntable plate 20,

preventing upward displacement of the turntable from the well or recess 34 defined by the base. Ring 33 may be removed to provide access to the bearings as described, for servicing.

In accordance with an important feature of the invention, an elongated track is located on the turntable and' extends transversely thereof. The track may, with unusual advantage, be defined by U or channel shaped structure 35 having a bottom plate 36 and upright side plates 37 attached to the underside of plate 20, as shown. The track may alternatively be in the form of an H-beam. In this regard, the carriages 28 and 30 and bearings 24 and 26 may be attached to and below the channel structure to directly receive loading transmitted from the supported column or post generally indicated at 38 in FIGS. 5 and 6.

Such loading is transmitted to the track by a roller or rollers 39 having an axis or axes 40 generally normal to the direction of track elongation, so that the rollers may roll relatively lengthwise of the track (actually the track moves relative to the roller) during occurrence of an earthquake, the turntable also rotating relative to the base to accommodate earth movement relative to the column or post. Rollers 39 engage track or runway surface 70.

A carriage for the roller may have the form of inverted channel shaped member 42 with a base plate 43 and side plates 44 carrying roller pivots 45. Another channel shaped member 46 may be connected with member 42 and project upwardly as shown through an opening 47 in the turntable. plate 20 for connection to, or to form part of a universal joint 48. The latter includes a body 49 pivotally connected at 50 to member 46 to rotate about axis 51, and pivotally connected at 52 to column end bearing 53 to rotate about axis 54. Offset axes 51 and 54 extend generally at right angles, as shown. Accordingly, the column may pivot universally with respect to the roller bearings 39, as the latter travel relatively along the track, with the turntable rtating, to accommodate earth movement during an earthquake. For enhanced stability, the track surface 70 may be slightly upwardly concave lengthwise thereof.

It will be noted that the carriage for the bearing is confined against lateral and upward displacement relative to the track. For this purpose, thrust members 56 may be rigidly attached to the U-shaped channel member 42 to project at the sides thereof for engagement with confining track side plates 37 and the overhanging plate structure 57.

It should also be noted, as in HO. 1, that the center line 58 of the bearing or bearings 39, which may coincide with the centerline of the column 38, is located in offset or eccentric relation with the turntable axis 12. This assures that the turntable will rotate in response to horizontal earth movement transmitted by the base in all directions except lengthwise of the track, and as to the latter the bearings 39 will travel relatively along with track, as described.

FlG. 7 shows multiple connections 60, as described, supporting columns or posts 61 extending beneath load imposing structure 62. The latter may comprise for example a building, bridge, heavy vessel, electrical equipment, or any heavy duty load imposing means.

The following additional advantages afforded by the described structure will now be appreciated: the sizes of the components may be varied as required by design criteria; hydraulic members may optionally be employed in the columns; the entire design of the connection can be made to conform to stable equilibrium as by forming the track surface with upward concavity as described; utility connections to a building can be made flexible to accommodate building lateral movement; and the earthquake resistant supports may be employed in such manner that other load bearing areas of the building (such as main shear walls, vaults, and basements) need not employ such supports.

The unit can be filled with a lubricant or a destructible plastic material in order to keep it free of debris, or concrete during the construction period.

I claim:

1. In an earthquake resistant column or post connection to a footing, the combination comprising a. a turntable and a base supporting the turntable for rotation about a generally upright axis,

b. an elongated track on and extending transversely of the turntable, and

0. column support means including a bearing carried by the track for movement relatively along the track in off-center relation to said axis accompanied by turntable rotation about-said axis in response to earthquake induced movement of said base.

2. The combination of claim 1 wherein said bearing comprises a roller engaging the track and said support means includes a universal joint carried by the roller, the universal joint and roller located to successively transmit column imposed loading to the track while accommodating angular shifting of the turntable and base relative to the column.

3. The combination of claim 2 wherein said track is defined by upwardly opening channel structure receiving said roller, said roller having an axis of rotation generally normal to the direction of track elongation.

4. The combination of claim 3 wherein said support means includes a carriage connected between the roller and said universal joint and confined by the track against lateral and upward displacement.

5. The combination of claim 1 including certain roller bearing means interposed between the turntable and the base to maintain the turntable centered with respect to said axis and transmit column imposed loading to the base.

6. The combination of claim 5 wherein said certain roller bearing means includes first rollers carried by the turntable proximate the periphery thereof to engage a generally circular upstanding wall defined by the base.

7. The combination of claim 6 wherein said certain roller bearing means includes second rollers located beneath the turntable and carried for rotation about axes extending generally radially relative to said upright axis.

8. The combination of claim 7 wherein said certain roller bearing means includes third rollers located beneath'the turntable and carried for rotation about axes extending generally radially outwardly as well as upwardly relative to said upright axis.

9. The combination of claim 8 wherein said second and third rollers are located generally beneath said track.

10. The combination of claim 1 including a building having multiple supporting columns, therebeing structure as defined in claim 1 supporting each of the .col-

umns. 

1. In an earthquake resistant column or post connection to a footing, the combination comprising a. a turntable and a base supporting the turntable for rotation about a generally upright axis, b. an elongated track on and extending transversely of the turntable, and c. column support means including a bearing carried by the track for movement relatively along the track in off-center relation to said axis accompanied by turntable rotation about said axis in response to earthquake induced movement of said base.
 2. The combination of claim 1 wherein said bearing comprises a roller engaging the track and said support means includes a universal joint carried by the roller, the universal joint and roller located to successively transmit column imposed loading to the track while accommodating angular shifting of the turntable and Base relative to the column.
 3. The combination of claim 2 wherein said track is defined by upwardly opening channel structure receiving said roller, said roller having an axis of rotation generally normal to the direction of track elongation.
 4. The combination of claim 3 wherein said support means includes a carriage connected between the roller and said universal joint and confined by the track against lateral and upward displacement.
 5. The combination of claim 1 including certain roller bearing means interposed between the turntable and the base to maintain the turntable centered with respect to said axis and transmit column imposed loading to the base.
 6. The combination of claim 5 wherein said certain roller bearing means includes first rollers carried by the turntable proximate the periphery thereof to engage a generally circular upstanding wall defined by the base.
 7. The combination of claim 6 wherein said certain roller bearing means includes second rollers located beneath the turntable and carried for rotation about axes extending generally radially relative to said upright axis.
 8. The combination of claim 7 wherein said certain roller bearing means includes third rollers located beneath the turntable and carried for rotation about axes extending generally radially outwardly as well as upwardly relative to said upright axis.
 9. The combination of claim 8 wherein said second and third rollers are located generally beneath said track.
 10. The combination of claim 1 including a building having multiple supporting columns, therebeing structure as defined in claim 1 supporting each of the columns. 